Needle selecting mechanism for multifeed circular knitting machines

ABSTRACT

A MULTI-FEED CIRCULAR KNITTING MACHINE HAVING A MECHANISM CAPABLE OF BRINGING ABOUT NEEDLE SELECTION EVEN THOUGH AN EXTREMELY SMALL CIRCUMERENTIAL SPACE IS AVAILABLE FOR THIS PURPOSE. A CAM CYLINDER CARRIES A PLURALITY OF CIRCUMFERENTIAL DISTRIBUTED CAM SETS EACH OF WHICH HAS AN INITIAL NEEDLE-SELECTING REGION AND A SUBSEQUENT MUCH WIDER KNITTING REGION. THE NEEDLE CYLINDER HAS LOWER SELECTING JACKS, UPPER NEEDLE JACKS, AND INTERMEDIATE SELECTION-TRANSMISSION JACKS. EACH CAM SET HAS AN UPPER KNITTING REGION AND A LOWER SELECTING REGION. THIS LOWER SELECTING REGION OF EACH CAM SET COACTS WITH THE LOWER JACKS AND THE INTERMEDIATE JACKS FOR RETAINING AT THE INTERMEDIATE JACKS SELECTIONS MADE WITH THE LOWER JACKS SO THAT IN THE LOWER SELECTING REGION OF EACH CAM SET SELECTIONS MAY INITIALLY BE MADE FOR NEEDLES WHICH ARE TO CARRY OUT KNITTING FUNCTIONS IN THE NEXT-FOLLOWING CAM SET. AT THIS NEXT-FOLLOWING CAM SET THERE IS IN CIRCUMFERENTIAL ALIGNMENT WITH THE INITIAL REGION THEREOF A CAMMING STRUCTURE WHICH TRANSMITS THE SELECTION RETAINED BY THE INTERMEDIATE JACKS TO THE UPPER JACKS SUBSTANTIALLY INSTANEOUS SELECTION OF NEEDLES IN AN EXTREMELY SMALL CIRCUMFERENTIAL SPACE AT THE INITIAL REGION OF EACH CAM SET.

Nov. 2, 1971 Filed June 16, 1969 JUAN BIBOLAS LLINAS NEEDLE SELECTINGMECHANISM FOR MULTI-FUUD CIRCULAR KNITTING MACHINES Ti Sheets-Shoat 1INVENTOR ATTORNEY Nov. 2 1971 JUAN BIBOLAS LLINAS NEEDLE SELECTINGMECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES 2 Sheets-Sheet 2Filed June 16, 1969 INVENTOR dbl W B/ISOL/YS 44/11 95 BY vM ATTORNEY$United States Patent 3,616,654 NEEDLE SELECTING MECHANISM FOR MULTI-FEED CIRCULAR KNITTING MACHINES Juan Bibolas Llinas, Calle San Pedro 46,Arenys de Mar, Barcelona, Spain Filed June 16, 1969, Ser. No. 833,469Int. Cl. D04b 9/06, 9/38 U.S. Cl. 66-25 4 Claims ABSTRACT OF THEDISCLOSURE A multi-feed circular knitting machine having a mechanismcapable of bringing about needle selection even though an extremelysmall circumferential space is available for this purpose. A camcylinder carries a plurality of circumferentially distributed cam setseach of which has an initial needle-selecting region and a subsequentmuch wider knitting region. The needle cylinder has lower selectingjacks, upper needle jacks, and intermediate selection-transmissionjacks. Each cam set has an upper knitting region and a lower selectingregion. This lower selecting region of each cam set coacts with thelower jacks and the intermediate jacks for retaining at the intermediatejacks selections made with the lower jacks so that in the lowerselecting region of each cam set selections may initially be madeforneedles which are to carry out knitting functions in the next-followingcam set. At this next-following cam set there is in circumferentialalignment with the initial region thereof a camming structure whichtransmits the selection retained by the intermediate jacks to the upperjacks substantially instantaneous selection of needles in an extremelysmall circumferential space at the initial region of each cam set.

BACKGROUND OF THE INVENTION The present invention relates to circularknitting machines.

In particular, the present invention relates to needleselectingmechanisms for circular knitting machines.

In multi-feed circular knitting machines, there are a plurality ofcircumferentially distributed substantially identical cam sets whichoperate sequentially on the needles to carry out the knitting functions.When fairly intricate pattern selections are required with a relativelylarge number of cam sets, particular difficulties are involved inconventional circular knitting machines in achieving the requiredselections.

Thus, in certain knitting machines which have a fixed unchangingdiameter it is only possible to situate a large number of sets byproviding each set with the smallest possible circumferential dimension.Thus, the smaller the circumferential dimension of the several sets thegreater the number thereof which can be circumferentially distributedabout the axis of a cylinder of a given diameter. Assuming that each camset has a given circumferential dimension of a given angular magnitude,it is essential to incorporate within each of these angular dimensions arelatively unchanging knitting region which follows an initial selectingregion where selection of those needles which are to carry out theknitting functions is made. Because of the fixed requirements for theknitting region of each cam set, when a large number thereof aresituated in a given cam cylinder, it becomes necessary to reduce theangular dimension of the initial selecting region, and this reduction inthe magnitude of the selecting region gives rise to considerableproblems because it is extremely difficult to make the required needledselection in an extremely small angular space. Thus, not only is needleselection required, but in addition erasing of previous selections isessential, so that this requirement of both erasing previous selectionsand making new selections renders the location of the erasing andselecting structure in a small angular space almost impossible toachieve.

Thus, at each knitting region of each cam set there will be an initialneedle-raising cam which raises a selected needle to an elevation whereit can carry out the knitting function, and this needle-raising cam ofeach knitting region is followed by a loop-forming cam which coacts withthe raised needle to pull the latter down so as to complete theformation of a loop. These latter cams and operations are well known inthe art and require a certain minimum space in order for the operationsto be carried out properly, so that when the total angular dimension ofa given cam set is reduced, it only becomes possible to reduce theangular dimension of the initial needle-selecting region of each camset.

SUMMARY OF THE INVENTION It is accordingly a primary object of thepresent invention to provide a solution to the above. problems.

In particular, it is an object of the invention to provide thepossibility of locating an extremely large number of cam sets in a givencam cylinder of a given diameter with each cam set having an exceedinglysmall initial selecting region while at the same time providing thestructure with the possibility of efficient selection of needles anderasing of previously made selections.

It is also an object of the present invention to provide aneedle-selecting mechanism capable of carrying out a substantiallyinstantaneous needle selection at the initial region of each cam set sothat an exceedingly small angular space is required for the initialregion of each cam set.

In particular, it is an object of the present invention to provide aneedle selecting mechanism which makes it possible for each cam set tocarry out not only knitting functions but simultaneously selectingfunctions in preparation for the instantaneous selection to be made atthe initial region of a next-following cam set.

Thus, in accordance with the invention the multi-feed circular knittingmachine includes coaxial needle and cam cylinders one of which rotateswith respect to the other. The cam cylinder carries a plurality of camsets which are substantially identical and which are circumferentiallydistributed about the axis of the cam cylinder with each cam set havingan initial needle-selecting region and a subsequent knitting regionwhich circumferentially is several times as great as the initialneedle-selecting region. In addition each cam set includes an upperportion for carrying out knitting functions and a lower portion forcarrying out selecting functions to be used in connection with aselection to be made at the next-following cam set. The needle cylindercarries beneath each needle an upper needle-operating jack, and spacedbelow the upper jack a lower selecting jack. Between each lowerselecting jack and the upper jack situated thereover is an intermediatejack for retaining a selection made with the lower jack and transmittingthis selection to the upper jack. Thus, while knitting functions areproceeding at the upper region of each cam set the lower region thereofcoacts with the intermediate jacks to place the latter in positions fortransmitting substantially instantaneously a selection to the upper jackat the initial region of the next-following cam set.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way ofexample in the accompanying drawings which form part of this applicationand in which:

FIG. 1 is a fragmentary developed view of the cam cylinder showing aplurality of cam sets and selecting means circumferentially arranged onenext to the other around the axis of the cylinder with FIG. 1 alsoschematically indicating at the upper part thereof the path of movementof the needle heads during the knitting operation;

FIG. 2 is a sectional elevation taken in a radial plane and showing aneedle and the jacks arranged in series therebeneath in a groove of theneedle cylinder.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, the path ofmovement of the upper knitting heads of the needles is indicatedschematically by the upper line 1 of FIG. 1. Also, FIG. 1 shows at itsupper left region the circumferential angular dimension B of each camset. This circumferential dimension B includes a relatively largeknitting region C and a relatively small initial selecting region A. Ashas been indicated above, it is essential at each knitting region C toprovide for raising of a selected needle, as by the cam 3 and loweringof the needle to form a loop by the loop-forming cam 2. Inasmuch asthese functions are essential and require a given circumferential space,then when the dimension B of an entire cam set is to be reduced, it isnot possible to reduce the dimension C, so that the result is that itbecomes necessary to reduce the initial selecting region A. Thus, itbecomes necessary to maintain the dimension C of each set constant, sothat as the number of sets are increased the circumferential dimension Adecreases to an extent where it is not longer possible to provide for aconvenient selection of the needles. Such selections are madeconventionally either directly on the needles or by selectionstransmitted thereto by jacks.

In accordance with the invention each cam set has a lower region whereselecting operations are carried out in connection with thenext-following cam set, while at each cam set a substantiallyinstantaneous selection is made at the initial selecting region A inaccordance with the selection operations carried out at the lower regionof the immediately preceding cam set. Thus, no matter how small the zoneA is, a proper selection can be made with the mechanism of theinvention.

The reasons why it is not possible to carry out the selections properlyin an exceedingly small angular space include not only the fact thatcertain structure is required for making selection but also the factthat certain structure is required for erasing previous selections.Therefore, sufficient space must be provided for erasing a previousselection and making a new selection. In a machine which has arelatively large number of cam sets, as, for example, a machine where 48cam sets are situated in a cam cylinder which has a diameter of 30inches, the available zone A becomes so small that it is no longerpossible for the required erasing and selecting operations to be carriedout effectively.

Thus, it will be noted that in each cam set there is in the upper regionthereof the cams 2 and 3 which carry out the knitting functions in themanner described above. Referring to FIG. 2, it will be seen that theneedles 15 are slidable in the vertical grooves of the needle cylinder,and in the illustrated example it is assumed that the needle cylinderrotates with respect to the cam cylinder shown in FIG. 1 so that thebutts 27 of the needles 15 coact with the cams 3 and 2 of each set tocarry out the knitting functions with the heads or top ends 19 of theneedles, these ends 19 moving along the path 1 indicated schematicallyat the upper part of FIG. 1.

As is apparent from FIG. 2, in each groove of the needle cylinder thereis an upper jack 14 situated beneath the needle 15 therein and directlycoacting with the needle to place a selected needle in a position to beraised by the cam 3 except when the latter is in an inactive horizontalposition. Thus, aligned circumferentially beneath the cam 3 of each camset is a cam 4 having a portion formed by cam 18 which coacts with abutt 28 of an upper jack 14 for raising the latter in a manner analogousto the manner in which the cam 3 raises a needle, and it is this cam 4which coacts with selected jacks 14 to bring about the raising ofselected needles. On the other hand, each knitting region includes adownwardly inclined camming edge .17 coacting with the butts of thesuccessive upper jacks 14 for lowering the latter into an engagementwith an erasing cam 5 which serves to displace each previously selectedjack 14 inwardly into the grove of the needle cylinder to a neutralposition in preparation for new selections which are made at the initialregion A of the next following cam set. Thus, actual needle selection ismade by way of the upper selecting jacks 14 with the selectionpreviously made in one cam set being erased by the cam 5 thereof priorto movement of the jacks 14 to the nextfollowing cam set.

Referring to FIG. 2 it will be seen that beneath each upperneedle-selecting jack 14 is an intermediate jack 13 which forms aselection-transmitting jack, as will be apparent from the descriptionwhich follows. Furthermore, beneath each selection-transmitting jack 13is a lower selecting jack 12 acted on directly by the selectingmechanism. Thus, with the structure of the invention the selections aremade directly on the lower selecting jacks 12 which coact with theintermediate jacks 13 in a manner enabling the latter to retain theselections so that these retained selections can be instantaneouslytransmitted to the upper jacks 14 at the initial regions A of theseveral cam sets.

Referring to FIG. 1, it is to be assumed that the needle cylinderrotates in the direction indicated by the upper substantially centralarrow of FIG. 1, to the left, as viewed in FIG. 1, so that the severalneedle and jack butts will arrive first at the initial region A and thenat the knitting region C of each cam set which has the dimension Bequaling the total of the circumferential regions A and C. At the lowerregion of each cam set there is an erasing cam 7 situatedcircumferentially in advance of the upper erasing cam 5 referred toabove. Each erasing earn 7 coacts with an upper butt 29 of a lower jack12 to displace previously selected lower jacks into the grooves of theneedle cylinder so as to thus situate all of the jacks 12 in neutralpositions within the grooves in preparation for new selections. The topends of the lower jacks 12 are operatively connected with the lower endsof the intermediate jacks 13 in such a way that when each jack 12 isdisplaced into the groove of the needle cylinder by the erasing cam 7the lower end of each intermediate jack 13 is also displaced into thegroove of the needle cylinder, thus displacing the butt of eachintermediate jack 13 into the needle cylinder in preparation for a newselection. However, because the erasing cam 7 act on the upper butts ofthe lower jacks 12, the bottom ends of the jacks 12 project outwardly soas to be situated in the path of movement of selecting levers. The mechanism includes a conventional lower selecting mechanism 8 in the form oflevers actuated by a suitable pattern wheel or the like so thatpreselected levers will project from the lever box 8 in order to engagethe lower ends of selected jacks 12. These lower ends will in this waybe displaced into the groove of the needle cylinder by the actuation ofthe selecting levers, while the non-selected jacks 12 will simply remainwith their lower ends projecting and their upper butts and upper endsdepressed into the needle grooves, thus maintaining these non-selectedlower jacks and the intermediate jacks 13 operatively connectedtherewith from participating in knitting functions to be carried out atthe next following cam set.

Each cam set of the invention includes at its lower region a selectingcam 6 provided with an upper camming edge having an initial lowercamming edge portion 10 located at the elevation of the butts 30 of theintermediate selection-retaining jacks 13. The result is that the inwardmovement of the bottom end of those jacks 12 which are selected by thepattern mechanism produces an outward movement of the butts of theintermediate jacks 13 which are operatively connected with the selectedjacks 12 so that these butts of the thus-selected intermediate jacks 13will ride along the camming edge portion 10. The butts of thenon-selected intermediate jacks 13 remain at the elevation of the edge10 but simply move circumferentially around the common axis of thecylinders without providing any participation of the jacks 14 situatedthereover and the needles 15 situated over the latter jacks 14 in theknitting operations.

Thus, the butt of each intermediate jack 13 which coacts with a selectedlower jack 12 will arrive at the inclined camming edge portion 11 of theselecting cam 6, this inclined portion 11 being situated at the trailingend of the initial or leading upper camming edge portion 10 of each cam6. The result is that this inclined camming edge portion 11 will raiseeach intermediate jack 13 which corresponds to and is operativelyconnected with a selected jack 12 to the elevation of the next cammingedge portion 16 of each cam 6. Thus, in the conventional cam box 8conventional selecting levers are actuated in a known way by the patternmechanism so as to bring about tilting of selected jacks 12 which willthus result in tilting of the intermediate selection-transmitting jacks13.

It is apparent, therefore, that with this construction while knittingfunctions are going forward in an upper region of each cam set inconnection with the upper jacks 14 and needles 15 situated thereover,selecting functions are taking place in the lower region of each cam setby way of the camming edge regions 10, 11, and 16 at the upper cammingedge of each selecting cam 6. With this construction the selections madeon the lower selecting jacks 12 are retained by the intermediate jacks13 which have their butts raised to the elevation of the camming edgeportion 16, with the thus raised intermediate jacks 13 being enabled inthis way to retain the selections made by way of the selecting mechanism8 and the lower jacks 12. Thus, during the knitting operations eachupper jack 14 which has been selected for participating in the knittingoperations will be raised by cam 4 and then lowered by the cam 17. Thelowering of each upper jack 14 by the cam 17 locates each jack 14 in aposition for engagement with the second erasing cam which acts upon theoperating butt of each upper jack 14 for displacing the latter furtherinto the groove of the needle cylinder to a neutral position inpreparation for the next selection.

As may be seen from FIG. 1, that cam set to which the dimensions AC areapplied is immediately preceded by an identical cam set where thereference characters for the edge portions of the upper camming edge forthe selection calm 6 are designated. At the same cam set where thereference characters for the upper edge portion of the selecting cam 6are located there is also designated the cam 18 past which thenon-selected upper jacks 14 move without raising the needles thereover.Thus, it will be seen that when the shoulder 31 of a jack 14 is withinthe groove 24, the butt 28 of the jack 14 will not reach the cam 18.This operation is further described below.

With the structure of the invention there is a second selectingmechanism 9 which serves to remove selected needles from among thosewhich have previously been selected, so that in effect a negativeselection is made by the selecting mechanism 9*. Thus, circumferentiallysubsequent to the selecting mechanism 8 there is the second selectingmechanism 9 which is also in the form of a lever box having selectinglevers actuated by the pattern mechanism. In the event that there is noprojecting lever at the lever box 9 beneath a given can set, then thepreviously selected intermediate jacks 13 will arrive with their buttsat the final inclined edge 19" of a given selecting cam 6. It is to benoted that this inclined edge 19' is located circumferentially inalignment with the initial region A of each cam set. Thus, the inclinededge 19' is located circumferentially just subsequent to the erasing cam5 of the immediately preceding cam set.

On the other hand, if a selecting lever of the lever box 9 does projectit will act upon a previously selected jack 12 to displace the latterfor retracting the cooperating intermediate jack 13 into the groove ofthe needle cylinder to a location where it will not be raised by thecamming edge 19. Thus, the levers of the mechanism 9 will act upon theupper butts of the jacks 12 to cause depression of the intermediatejacks 13 into the needle grooves so as to cancel a selection previouslymade with the lever box 8.

In the above-described manner those selected intermediate jacks 13 whichdo not have the selections cancelled will rise along the inclinedcamming edges 19' precisely at the initial selecting region A of eachcam set. Thus, it will be seen that the mechanism 9 forms a secondselecting means determining those previously selected lower jacks whichwill be retracted before moving upwardly along the second inclinedcamming edge 19.

As may be seen from FIG. 2, the upward movement of each intermediateselection-retaining and transmitting jack 13 causes the upper end 20thereof, which terminates in an upper bevelled surface, to engage thelower equally bevelled end surface 21 of the upper needle-operating jack14. This lower end 21 is raised to the elevation of the dot-dash line 22indicated in FIG. 2 through the action of the inclined edge 19 on thebutt of the intermediate jack 13. Each needle groove is provided with arecess 24 having at its upper end the inclined portion 23 coacting witha shoulder 31 of each jack 14 for displacing the latter out of thegroove when each jack 14 is raised by an intermediate jack 13. As isapparent from FIG. 2, the movements at this time in connection with thetransmission of the selection to a jack 14 by a jack 13 and movement ofthe jack 14 radially are extremely small. However, only this smallextent of movement is required at the initial region A of each cam setto place the butt of the selected jack 14 in engagement with the cammingedge 25 which transfers a selected jack 14 to the part of cam 4 formedby cam 18 which raises the jack 14 and thus also raises the needle 15thereover so that the butt of this needle can be acted upon by theraising cam 3. In this way selected needles are raised to participate inthe knitting functions in a manner described above. It is common andwell known in machines of the type described above and disclosed in thedrawing to provide cams 3 each of which may be oscillated from theillustrated position to a substantially horizontal position, in the sameway as illustrated for the cam 18. The cams 3 are used in theillustrated inclined positions in connection with plain knitting.However, when patterning operations are carried out the cams 3 areplaced in the horizontal positions illustrated for the cam 18 so that inthis case the needles are raised by means of the upper jacks 14 which,when selected, have their butts situated within reach of the earns 18which are left at this time at their operative inclined positions.

Thus, it will be seen that with the structure of the invention eventhough the initial selecting region A is maintained at an extremelysmall magnitude, in a circumferential direction, and even though theselection of a given upper jack 14 is made substantially instantaneouslywith an exceedingly small extent of movement thereof, nevertheless byutilizing the lower region of the immediately preceding cam set forpreliminary selecting functions it becomes possible to carry out therequired erasing and selecting operations in a highly effective, fullyefiicient manner while at the same time providing for each cam set anexceedingly small circumferential dimension B which need only beslightly greater than the minimum required circumferential space C wherethe knitting functions are carried out.

FIG. 2 illustrates conventional components which do not form part of theinvention. Thus, FIG. 2 illustrates the needle cylinder components 32and 33 which are interconnected by the bolts 34. At the lower part ofFIG. 2 is illustrated the crown wheel 35 for driving the cylinder. Thiswheel is fixed to the cylinder by screws 36 and is centered by screws 37and nuts 38. FIG. 2 also shows one of the several elongated steel strips4-1 which define between themselves the grooves of the needle cylinder.These strips 41 have the anchoring projections 39 and 40 received in theanchoring grooves 42. FIG. 2 also shows the lower jack rings 43 and theneedle holding spring ring 44.

At the upper region of FIG. 2 there is fragmentarily illustrated thedish or plate 45 which carries the radial crown 46 which is fixed to thesupport 45 by way of the bolts 47. Also, FIG. 2 shows the radiallyextending steel strips 48 which correspond to the strips 41 and form thedial grooves, these strips 48 respectively having the anchoringprojections 49 received in the anchoring groove 50. Thus, these strips48 form the radial needle grooves 51 for the radial needles 52 whichhave the two different butts '53 and 54.

What is claimed is:

1. In a multi-feed circular knitting machine, coaxial cam and needlecylinders one of which rotates with respect to the other, said camcylinder having a plurality of substantially identical cam setscircumferentially distributed abou the axis of said cam cylinder andlocated in a series one after the other for sequentially carrying outknitting and selecting functions, each cam set having an upper knittingportion and a lower selecting portion for participating in the selectionof needles which carry out knitting functions in the next-following camset, said needle cylinder having upper jacks for coacting with needlesover said upper jacks, lower jacks respectively situated beneath andspaced from said upper jacks, and intermediate jacks situated betweensaid lower and upper jacks so that beneath each needle there is an upperjack situated over an intermediate jack which in turn is situated over alower jack, said selecting portion of each cam set coacting with saidlower jacks for making a selection for the next-following cam set whilethe upper portion of each cam set carries out the knitting functionswith the upper jacks and needles thereover, and said intermediate jacksretaining the selections made with said lower jacks, the lower portionsof the cam sets coacting with said intermediate jacks for transmittingselections therefrom to the upper jacks at the instant when the latterand the needles become aligned with the next-following cam set so thateach cam set has an initial needle-selecting region where substantiallyinstantaneous needle selection is carried out in an exceedingly smallcircumferential space, each cam set including an upper erasing cam and alower erasing cam situated circumferentially in advance of said uppererasing cam, said lower erasing cam placing previously selected lowerjacks in neutral positions for selectively receiving a new selection andsaid upper erasing cams placing said upper jacks in neutral positions toreceive upon attaining alignment with the next following set theselection retained by the intermediate jacks, a selecting means beinglocated beneath each cam set circumferentially in advance of said uppererasing cam and subsequent to said lower erasing cam for making aselection of a lower jack which has been placed in a neutral position bysaid lower erasing cam, a second selecting means being located beneatheach cam set circumferentially subsequent to the first-mentionedselecting means for placing lower jacks previously selected by saidfirstmentioned selecting means in neutral non-selecting positions justprior to transmission of the selection to the upper jacks by theintermediate jacks, so that the second selecting means provides afurther selection retracting selected lower and intermediate jacks fromselecting positions where a selection will be transmitted to an upperjack.

2. The combination of claim 1 and wherein said lower portion of each camset which carries out the selecting function includes a selecting camhaving an upper camming edge provided with a leading lower selectingportion, an upwardly inclined camming edge extending upwardly from atrailing end of said leading edge portion, a second upper selecting edgeportion extending from said inclined edge portion, and a second inclinededge portion extending upwardly from said second edge portion, saidfirst-mentioned selecting means placing selected lower jacks with buttsthereof in engagement with said leading lower camming edge to be guidedthereby to the inclined edge extending from the trailing end of saidleading camming edge to be raised to said second, upper camming edge,and said second selecting means determining those previously selectedlower jacks which will be retracted before moving upwardly along saidsecond inclined camming edge.

3. The combination of claim 2 and wherein said second inclined cammingedge is situated circumferentially in line with the initial region ofeach cam set where the selection is transmitted to an upper jack.

4. The combination of claim 3 and wherein said second inclined cammingedge is situated at each set circumferentially in advance of the lowererasing cam.

References Cited UNITED STATES PATENTS 2,019,396 10/1935 Deans et a1.6650 B 2,025,463 12/1935 Lombardi 6650 A 2,974,506 3/1961 Lawson 66--5OX 3,063,269 11/1962 Losert et a1. 66-50 X 3,240,032 3/1966 Carrotte 6650X 3,457,734 7/1969 Millar 6650 X FOREIGN PATENTS 820,832 9/1959 GreatBritain 6614 OTHER REFERENCES German Printed Application No. 1,199,425,Losert, August 1965.

WILLIAM CARTER REYNOLDS, Primary Examiner US. Cl. X.R. 66--42

